flatten folder structure, fix collision boxes and gui/fp/tp transforms

ButterflyPins/Systems/ButterflyPinsModSystem.cs

@@ -0,0 +1,15 @@
+using ButterflyPins.BlockEntities;
+using ButterflyPins.Blocks;
+using Vintagestory.API.Common;
+
+namespace ButterflyPins.Systems;
+
+public class ButterflyPinsModSystem : ModSystem
+{
+    public override void Start(ICoreAPI api)
+    {
+        api.RegisterBlockClass("BlockButterflyPinBoard", typeof(BlockButterflyPinBoard));
+        api.RegisterBlockEntityClass("ButterflyPinBoard", typeof(BlockEntityButterflyPinBoard));
+        api.Logger.Notification("ButterflyPins loaded");
+    }
+}